The invention relates to electrical couplings and particular to assemblies which are useful in the electrical coupling of railway car body wiring to an electrical coupler contact. The connection between cars is made by means of apparatus such as that shown in U.S. Pat. No. 4,743,201 assigned to the same assignee as the present invention. The present inventor was a co-inventor of that apparatus.
More specifically, the interconnection of electrical wires from one rail car to the next is achieved by means of connectors arranged in dielectric blocks which are forced together as by clamping. In one transit car design, electrical contact from one wire to another is achieved by means of a butt fit between a moveable contact plunger in one block and a stationary contact pen in another block at the connection interface. This electrical interface is in addition to mechanical coupling elements which hold the two railway cars together and thus hold the respective dielectric blocks on the respective cars in engagement.
Various means have been provided to couple the car body wiring to the electrical coupler contacts in the dielectric blocks. These include the following:
1. Pin and socket. This construction has the disadvantage that the contact force is dependent on the spring force of a split pin. More specifically, an axially split pin engages an elongated socket. More specifically, the pin, in a typical embodiment, is split axially in two planes disposed at right angels to each other. The axially extending segments of the pin are spring biased outwardly to engage the wall of the elongated socket somewhat in the manner of a banana plug. This rather poor connection tended to overheat due to vibration or large currents. The overheating would cause a loss of spring force which compounded the overheating problem resulting in a failure of the electrical connection. PA1 2. Solder connection. This approach avoided the overheating problem but does not provide for ease of separability of the components. PA1 3. Ring terminals. For some applications, commercially available ring terminals have been used. This method provides a low resistance separable connection. However, the physical size precludes usage in some applications. In addition, it may be difficult in some cases to provide adequate insulation of the entire connection while maintaining the separability feature. PA1 4. Commercially available Sta-Kon (trademark) terminals. Some applications have used such commercially available male tab with a cooperating female connection. This construction can be easily insulated and requires little space, however, such connections are subject to loosening due to vibrations and are not at all suitable for a large current loads.
It is an object of the invention to provide a connection which provides a low contact resistance path between the train line wires and the coupler contacts and which is also easily separable.
Another object of the invention is to provide apparatus which is capable of carrying large current loads in excesss of 40 amperes continuously.
Still another object of the invention is to provide a novel and improved means of connecting the electrical wires of the railway car to that car's electrical coupler contacts with a minimal voltage drop across the connection while providing maximum reliability for apparatus which is easy to assemble and disassemble.
Another object of the invention is to provide apparatus which will lock together in a very positive manner.
Yet another object of the invention is to provide apparatus which can be easily disconnected despite the locking nature of the connection made by the apparatus.
Still another objection of the invention is to provide apparatus which will be substantially immune to ambient contaminants and the formation of an oxide coating or other film growth which would degrade the electrical connection.